The hydrogenation reactions relate to basic industrial processes that are usually realized over a catalyst, in particular, for the synthesis of alicyclic and cyclic saturated organic compounds, high-quality benzine, etc.
According to the written publications known in the art (see Grove D. E. Plat. Met., 2002, 46, (2) 92), about 75% of the industrial hydrogenation processes are realized over the Pd/C catalyst, which contains 5% of metal palladium. The rich variety of palladium's catalytic properties allows using it in almost all reactions necessary for the organic synthesis. Therefore, at present, Pd/C is the most suitable system for realizing the processes of the catalytic organic synthesis.
A known method for producing a palladium-containing hydrogenation catalyst consists in reducing divalent palladium from the initial compound thereof and precipitating the thus reduced palladium on a carbon material, wherein the initial compounds are embodied in the form of Pd (II) complexes, see Tsuji J. Palladium reagents and catalysts-innovations in organic syntheses. John Wiley & sons, Chichester. 1995. 595 p.; Grove D. E. Plat. Met., 2002, 46, (1) 48.
Another known method for producing a palladium-containing hydrogenation catalyst consists in reducing divalent palladium from the initial compound thereof and precipitating the thus reduced palladium on a carbon material, wherein the initial compound in embodied in the form of palladium chloride (II), see H. M. Colquhoun, Y. Holton, et alii, “New Pathways for Organic Synthesis” (   ), translated from English by M. S. Ermolenko and V. G. Kiseleva, Moscow,  (“Chemistry”), 1989, 361 p., 2nd paragraph counting from the top of the page.
The palladium chloride (8.2 g) solution in hydrochloric acid (20 ml of concentrated acid in 50 ml of water) is heated during 2 hours, then added, while constantly stirring, to a hot (80° C.) coal suspension in water (93 g of coal in 1.2 l of water), wherein the coal has previously been washed with nitric acid.
Coal of almost any type can be used, provided that said coal has a sufficiently large specific surface area, has been washed with nitric acid (10%) during 2-3 hours, subsequently washed with water in order to eliminate the acid, and dried at 100° C. Then the formaldehyde is added (8 ml of 37% solution) and subsequently the sodium hydroxide solution is added until a strong alkaline reaction is achieved. After 10 minutes the thus obtained catalyst is filtered out, washed with water (10×250 ml) and vacuum dried over calcium chloride. The palladium outlet equals 5% for 93-98% coal.
This method is taken as a prototype of the present invention.
The disadvantage of said method is in that the catalyst produced according to this method exhibits a low catalytic activity and operates only at high temperatures (higher than 60° C.) and high pressure (higher than 5 gauge atmospheres). The reason for said disadvantage is the difficulty of activation of the reaction centers of the catalyst produced according to the prototype method.